1. Technical Field
The present invention is directed to cabling and transmission lines and, in particular, to a coaxial cable arrangement and a compensation circuit for matching impedances, such as for a speaker wire system used for audio applications.
2. Background Art
When a source of power, such as an audio signal source, etc., feeds a resistive load, the maximum available power is delivered to the load when the impedance of the load matches the impedance of the source. If the impedance of the load is greater than the impedance of the source, the load may be underutilized. Alternatively, if the impedance of the load is sufficiently less than the impedance of the source, the current draw by the load increases and may cause the power supply to fail. Moreover, if the impedance of the load does not match the impedance of the source, some of the power generated by the source is not transferred to the load but is instead reflected back towards the source.
As an example, an audio signal source, such as an audio amplifier, may be connected to a speaker over a coaxial cable or other speaker cable. Preferably, the combined impedance of the speaker and the speaker cable is matched to the impedance of the amplifier to prevent signal reflections. In another audio application, an audio transducer, such as a microphone or a tape head, may be connected to a load, such as a recorder, using a coaxial cable or other cable. The combined impedance of the cable and the load is preferably matched to the impedance of the transducer to ensure better control of the transducer performance by the electrical damping effect of the load. If the impedances are mismatched, unwanted resonances may occur and may result in a much flatter response by the transducer.